Welding gun



FIGA.

ATToRNEvs Patented Dec. 28, 1948 UNITED STATES OFFICE 2,457,606 wELnmG GUN Charles Senn, Detroit, Mich.

Application May 3, 194s, serial No. 24,742

The invention relates to welding guns and has for its object the obtaining of a simple construction which may be used singly or in multiple, and in which the electrode is alternatively pressed against the work or retracted therefrom by uid pressure.

It is a further object to obtain a construction in which the movable elements of the gun are firmlyv held by the stationary elements thereof, while still providing for the required relative movement thereof.

Still further it is an object of the invention to obtain-a construction provided with an electrified head for carrying the electrode and to which it is detachably secured, said head having also incorporated therein cooling means for itself and the electrode shank. Withthese -andother. ob jects in view, the invention consists in the construction as hereinafter set forth.

In the drawings:

Fig. 1 is a central, longitudinal section through the Welding gun;

Fig. 2 is a cross-section on line 2-2, Fig. l;

and f Fig. 3 is a cross-section on line 3 3, Fig. 1

A is a head to which the electrode B is secured preferably by providing the latter with a tapered shank engaging a corresponding socket in the head. This head has projecting portion A for attachment of the cable which electriiies the head and electrode. Between the portion A and the electrode is an oblique portion A2 in which are formed parallel passages A3 and A4 for a liquid cooling system. The passage A3 directly connects with the recess Which receives the shank of the electrode, said shank being hollow for a portion of its length. The other passage A4 connects with a small diametertube Cl which extends outward from the head and into the space within said electrode to near the outer end theres. of. Thus when the passages A3 and A4 are coupled to external flexible conduits (not shown) cooling fluid will be circulated through both the head and electrode shank. y

The head A-has secured thereto to extend rearward therefrom a cylinder D which, however, is electrically insulated from said head. This is accomplished by providing the head with a shank portion A5, which is smaller than the bore of the cylinder and extends into the outer end portion thereof. A shank and the cylinder and is provided With an outwardly extending flange E' for separating the' l passing v`there'through and -out through the end of the cylinder from the head. These parts An insulator bushing E is between the 4 claims. (c1. 219-4) are secured to each other by a key such as n.455

tapered pin F which passes diametrically through the cylinder and a bore in said shank, said bore being lined by an insulator sleeve E3. Thus the head and -cylinder will be firmly connected to, but electrically insulated from, each other. The cylinder D is surrounded by a casing member G, and there is also a member H extending within the cylinder and having a piston head H at its outer` end for fitting the cylinder bore. In rear of said piston head is a cylindrical shank portion H`4 which is of slightly smaller diameter and which ts a smaller diameter bore D' at the rear end of the cylinder D. The casing G is also provided with a rear portion G which ts the shank H and is connected thereto by one or more keys I. The shank extends out and beyond the portion G of the casing and terminates in a threaded portion H3 engaged by a nut J for clamping the structure to a suitable support K. The shank portion H2 of the member H has a longitudinal bore H4 therein connecting with the transverse bores H5 and H8, Which together form a passageway connecting to the space between the shank and the cylinder on the rear side of the piston head. A tube L of smaller diameter than Athe bore v H4 passes through the same and through the piston head H' connecting with the latter. The rear end of this tube engages a plug L which separates it from the bore H4 but connects it with a passage through the end of the shank H2. The plug L' is brazed or welded to the shank H2 and the threadedfpcrtion H3 to form thereof a rigid structure. The passage through the end of the shank is connected by a conduit (not shown) to the source of fluid under pressure and another fluid conduit (also not shown) is connected to the bore H6. To prevent relative rotation of the casing G and cylinder D, the latter is provided with a attened portion extending for a, portion of its length, and a key M passing through a transverse bore in the casing has a flattened central portion which engages'the ilattened portion of the cylinder D, while heads M at its opposite ends hold the key from disengagement. A piston N is placed withinV thecylinder'between the piston head H and the bushing E and a packing ring O forms -a peripheral seal for said piston. Similar packing rings O and O2 seal, respectively, the piston head H' ,and the portion of said cylinder which engages the shank H2.

The parts being constructed as above described are'assenjihled,asv follows. y The member H is Viirst inserted intov the large end ,of the cylinder D smaller diai'neterlierre1D.` Both Iof .these parts' REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 2,256,028 Jardine Sept. 16, 1941 2,341,133 Weightman Feb. 8, 1944 FOREIGN PATENTS Number Country Date 782,691 France Mar. 25, 1935 

